code: def _assemble_node(self, node_id):
      if self._tree.children_left[node_id] == TREE_LEAF:
          return self._assemble_leaf(node_id)
      else:
          return self._assemble_branch(node_id)
  
file_path: m2cgen/m2cgen/assemblers/tree.py
imports: from m2cgen import ast
  from m2cgen.assemblers.base import ModelAssembler
  from m2cgen.assemblers.utils import lte
label_desc: Use image node_id 3 for calling the TreeModelAssembler obj's underlying member method code with example usage: obj._assemble_node(node_id) and returns: self, self